/*****************************************************************************
 * This source file is part of SCREEN (SCalable REndering ENgine)            *
 *                                                                           *
 * Copyright (c) 2008-2012 Ratouit Thomas                                    *
 *                                                                           *
 * This program is free software; you can redistribute it and/or modify it   *
 * under the terms of the GNU Lesser General Public License as published by  *
 * the Free Software Foundation; either version 3 of the License, or (at     *
 * your option) any later version.                                           *
 *                                                                           *
 * This program is distributed in the hope that it will be useful, but       *
 * WITHOUT ANY WARRANTY; without even the implied warranty of                *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser   *
 * General Public License for more details.                                  *
 *                                                                           *
 * You should have received a copy of the GNU Lesser General Public License  *
 * along with this program; if not, write to the Free Software Foundation,   *
 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA, or go to   *
 * http://www.gnu.org/copyleft/lesser.txt.                                   *
 *****************************************************************************/

#ifndef SCREEN_OPENGL_BUFFER_H
#define SCREEN_OPENGL_BUFFER_H

#include <screen/core/objects/BufferBase.h>
#include <screen/opengl/OpenGLRenderer.h>
#include <screen/core/Enums.h>
#include <screen/utils/Export.h>

using screen::core::objects::BufferBase;

static unsigned long glLockFlags[] = {
	GL_READ_WRITE_ARB,
	GL_READ_ONLY_ARB,
	GL_WRITE_ONLY_ARB
};

namespace screen {
	namespace opengl {
	    template <int Type>
	    class OpenGLBuffer : public BufferBase{
	    public :
	
	    	OpenGLBuffer(unsigned long count, unsigned int buffer)
	    		:BufferBase(count),buffer(buffer)
	    	{}
	        
	    	virtual ~OpenGLBuffer(){
	    		if (buffer)
	    			OpenGLRenderer::glDeleteBuffersARB(1, &buffer);
	    	}

	        unsigned int getBuffer() const{
	        	return buffer;
	        }
	
	    private :
	        void* lock(unsigned long offset, unsigned long size, screen::core::LockFlag flags){
	            OpenGLRenderer::glBindBufferARB(Type, buffer);
	            unsigned char* buffer2 = reinterpret_cast<unsigned char*>(OpenGLRenderer::glMapBufferARB(Type, glLockFlags[flags]));
	            return buffer2 + offset;
	        }
	        
	        void unlock(){
	        	OpenGLRenderer::glUnmapBufferARB(Type);
	        }
	        
	        unsigned int buffer; ///< Identifiant du buffer opengl
	    };
	
	    typedef OpenGLBuffer<GL_ARRAY_BUFFER_ARB>         OpenGLVertexBuffer;
	    typedef OpenGLBuffer<GL_ELEMENT_ARRAY_BUFFER_ARB> OpenGLIndexBuffer;
	}
}

#endif
